Multi-leg one-loop gravity amplitudes from gauge theory

275

376

Abstract:We derive an explicit formula for factorizing an n-point closed string amplitude into open string amplitudes. Our results are phrased in terms of a momentum kernel which in the limit of infinite string tension reduces to the corresponding field theory kernel. The same momentum kernel encodes the monodromy relations which lead to the minimal basis of color-ordered amplitudes in Yang-Mills theory. There are interesting consequences of the momentum kernel pertaining to soft limits of amplitudes. We also comment on surprising links between gravity and certain combinations of kinematic and color factors in gauge theory.

“…Interestingly, tree-level gravity amplitudes have a universal behavior when taking one graviton to be soft, a classic result due to Weinberg [4,29] …”

Section: Soft Limit Of Graviton Amplitudes At Tree-levelmentioning

confidence: 99%

“…The explicit n-point formula that was conjectured in ref. [4] has been proven as one particular case [3].…”

Section: Introductionmentioning

confidence: 98%

The momentum kernel of gauge and gravity theories

Bjerrum-Bohr¹,

Damgaard²,

Søndergaard³

et al. 2011

275

376

“…3 The function S is nothing, but the f -function defined in [13] with more symmetric and improved expression…”

Section: )mentioning

confidence: 99%

“…The leading, subleading and subsubleading orders of soft factors are given by 1 The leading soft factor S (0) GR is not corrected to all loop orders is shown in [5,6,13] while the general subleading behavior of soft gluons and gravitons has also been discussed in [14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Note on soft graviton theorem by KLT relation

Feng

et al. 2014

Recently, new soft graviton theorem proposed by Cachazo and Strominger has inspired a lot of works. In this note, we use the KLT-formula to investigate the theorem. We have shown how the soft behavior of color ordered Yang-Mills amplitudes can be combined with KLT relation to give the soft behavior of gravity amplitudes. As a byproduct, we find two nontrivial identities of the KLT momentum kernel must hold.

“…If both 1 and 2 are external particles this reduces to the well known behavior of gravity amplitudes in the collinear limit [80,81],…”

Section: Collinear Behaviormentioning

confidence: 90%

Gravity on-shell diagrams

Herrmann

Trnka

2016

We study on-shell diagrams for gravity theories with any number of supersymmetries and find a compact Grassmannian formula in terms of edge variables of the graphs. Unlike in gauge theory where the analogous form involves only d log-factors, in gravity there is a non-trivial numerator as well as higher degree poles in the edge variables. Based on the structure of the Grassmannian formula for N = 8 supergravity we conjecture that gravity loop amplitudes also possess similar properties. In particular, we find that there are only logarithmic singularities on cuts with finite loop momentum and that poles at infinity are present, in complete agreement with the conjecture presented in [1].